The importance of anopheles funestus in the transmission of malaria in Western Kenya

Abstract

A longitudinal study was undertaken of the seasonal abundance, malaria infection and infectivity rates of member species of the anopheles gambiae complex and An.funestus in Western Kenya at different altitudes. An.arabensis was the most abundant vector in human bait catches at a ratio of 3:1 of An.gambiae and two times that of An.fenesus. At Ahero both the sporozoite rate (3.0) and entomological inoculation rate (0.02 infective bites of An.funestus)were significantly higher than those of An.arabiensis (0.4 and 0.006 inefective bites)all year round. At Rota-Kisian, however, although the sporozoite rate of 4.7 for An. gambiae was higher than that of An. Funestus (4.30 in some months of the year, the entomological inoculation rate for An.funestus (0.065 infective bites) was still significantly higher than that of 0.022 infective bites of An.gambiae in most times of the year. It is concluded that despite the high man-biting rates of An.arabiensis and An.gambiae, An.funestus appears to be the most important vector of all the three in malaria transmission although its transmission potential seems to be underestimated in most studies.